Annunciator.



0. M. LEICH.. ANNuNclArom 'APPLICATION FILED APR. I6 |915.

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Patented Feb. 6, 1917.

STATES PATENT OFFICE.

OSCAR IVI. LEICH, 0F GENOA, ILLINOIS, ASSIGNOR TO CRACRAFII, LEICH ELECTRIC COMPANY,r OF GENOA, ILLINOIS.

ANN UNCIATOR.

Specification of Letters Patent.

Patented Feb. 6, 1917.

Application led April 16, 1915. Serial-No. 21,783.

To all whom t may concern:

Be it lznown that I, 'OSCAR M. LnioH, a citizen of the United States, residing at Genoa, in the county of Dekalb and State of Illinois, have invented a certain new and useful Improvement in Annunciators, of which the following is a' full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to annunciators, and more particularly to the annunciators or drop shutters used for telephone switchboards. More particularly, my invention is designed to improve and modify the responsive characteristics of the armature of drops in which the armature has a short shutter arm.

A form of annunciator with a short shutter arm is disclosedV in my Patent No. 1,116,598, issued Nov. 10,1914. I will show my invention herein more particularly as applied to the annunciator set forth in my said patent. This particular annunciator is of the combined drop and jack type although of course the invention is equally applicable to annunciators not combined with jacks.

It is generally understood that the short arm annunciators are more sensitive than the aiiiiuiiciators having the elongated shutter arms, and for this reason it is desirable to maintain the use of the short arm'annunciator if possible. It is vfound that when the long arm annunciators are used that the shutter arms rattle during the 'time the signal is coming in, thus giving an indication to the operator of the code that is beingy transmitted over the line. If there is only one series of vibrations, the' operatorlrnows that the call is for central, if there areseveral interrupted series of vibrations, the operator knows that a code is being transmitted over the line, such as one ring, two rings, or the like, and the operator does not plug into the corresponding j ack of the calling line, but merely restores the drop shut'- ter, thus saving a lot of time. It has been found that the short army annunciator does not lend itself to this use as theshortarm;

with its armature is drawn up and remains drawn up at least sufficiently so as not to permit the operator to distinguish any code.

This invention herein is designed thus to adapt short arm annunciators to give this code indication without sacrificing any of the Isensitiveness of this short arm annunciator type.

I will explain my invention more in detail by referring to the accompanying drawing in' which- Figure 1 is a side view partly in section 'of an annunciator constructed in accordance with my invention;

Fig. 2 is a top view thereof, and

Fig. 3 is an enlarged view similar to Fig. 1.

My improved annunciator may be one of a bank which are supposed to be mounted vupon a front plate 1. Rearwardly from this front plate extends side arms 2, 2, which toward the left form a pocket 3 carrying the coil and shell 4. In this specific form herein outlined the coil` 'has a protruding core 5 lwhich'projects into a magnetic pole piece 6,

which magnetic pole piece is preferably held in a bridge 7 between the arms 2. A jack structure 8 is likewise shown to indicate a combined self-restoring drop and jack structure, the restoring'spring being shown at 9.

yThe side plates 2'falso carry a spindle or shaft 10 which supports the armature 11. The armature as shown has two ribs 12 j punched upwardly out of the metal of the 6, no adjustment between the armature and pole piece being required when a drop coil is changed asthepolepiece and armature are permanently mounted in position. The armature 11 carries the shutter arm 13 of the short type which controls the shutter 14.

Now whenever the electromagnet 4 is actuated, the shutter of course falls. Now in order to cause the armature 11 and arm 13 to rattle or vibrate due to the impulses, I

provide a spring 15 bent somewhat in the form of an up-turned J (Fig. 2), which spring is riveted'to the armature by the rivet 16. This spring has a rectangular. eX- tending leg 17 which projects through a slot 18 cut through the armature 11. The leg 17 of the spring does not no-rmally touch the pole piece 6 as most clearly apparent from Fig. 3. This leg is also arranged of such length that the shutter 14 is released by the shutter arm 13 before the leg 17 of the spring 15 reaches the pole piece 6. Thus the sensitiveness of the annunciator is not reduced.

The spring however pushes the armature away from the pole piece during the interval between each pulsatioii, and thus causes the rattling characteristic of the long arm annunciators which is of such aid and benefit to the operator in saving useless work.

From what has been thus described it will be seen that without the sacriiice of its sensitive qualities, the additional indicatingV qualities are provided. As before stated the invention is not limited to the particular form of drop or drop and jack here illustrated, but is applicable in some equivalent manner to other types.

Having however. thus described one for which my invention may take, what I claim as new and desire to secure by Letters Patent is:

l. A drop annunciator having a drop shutter, an actuating electromagnet, a shutter arm to control said drop shutter, an armature for actuating said shutter arm, said'shutter arm being of the short type and extending between said electromagnet and said drop shutter, and a spring interposed between said armature and said electromagnet, said spring beingrof a substantially U- shape having one extremity fastened to said armature, and having the opposite extremity adapted to engage said electromagnet.

2. A drop annunciator having a drop shutter, an actuating electromagnet, a shutter arm to control said drop shutter, an armature for actuating said shutter arm, said shutter arm being of the short type and extending between said electroinagnet and said drop shutter, and a spring interposed between said armature and said electromagnet operative after the release of said drop shutter by said shutter arm to establish a yielding restraint against the attractive i'orce of said electromagnet, Said spring being of a substantially U-shape having one extremity fastened to said armature, and having the opposite extremity adapted to engage said electromagnet.

3. A drop annunciator having a drop shutter, an actuating electromagnet, a shutter arm to control said drop shutter adapted to release said shutter from said shutter arm when said shutter arm is actuated, a gravity restoredV armature carrying said shutter arm, said shutter arm being of the short type and extending between the rear extremity of said electromagnet and said drop shutter, said shutter arm and armature having a low moment of inertia, yielding means interposed between the said armature and said electromagnet, and positive means for controlling said yielding means whereby said yielding means is inoperative to effectively oppose the movement oit' said armature until the shutter arm has released the shutter, said yielding means thereafter causing a rattling of said armature when undulatorj,7 currents are energizing said electromagnet.

4f. A drop annunciator having a drop shutter, an actuating electromagnet, a shutter arm to control said drop shutter adapted to release said shutter from said shutter arm when said shutter arm is actuated, a gravity. restored armature carrying said shutter arm, said shutter arm being of the short type and extending between the near extremity ofy said electromagnet and said drop shutter, said shutter arm and armature having a low moment of inertia, a spring interposed between said armature and said electromagnet, and positive means for controlling said spring whereby said spring is inoperative to effectively oppose the movevment of said armature until the shutter arm has released the shutter, said spring thereafter causing a rattling of Vsaid armature when undulatoryv currents are energizing said electromagnet.

In witness whereof, I hereunto subscribe kmy name this 23rd day of March, A. D. 1915.

OSCAR M. LECH.

Witnesses HAZEL A. JONES, Max W. ZABEL.

Copies of this patentmay be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

